How I Built a Markdown Editor for Android That Doesn't Squeeze Out Your Productivity

Writing documentation, drafting blog posts, or taking structured notes on a phone is generally a frustrating experience. While desktop markdown editors have evolved to offer smooth, distraction-free environments, mobile tools often force you to choose between a clunky text input area or a heavily restricted UI.

As a developer, I frequently get ideas for technical posts or need to update repository readmes while away from my desk. The struggle of manually typing backticks, hashes, and brackets on a standard mobile keyboard—coupled with the lack of instant previews—led me to build AIMarkdownPro Editor.

Here is the story of how I tackled the challenges of mobile markdown editing, the tech stack I chose, and what I learned along the way.

The Main Problem: Mobile Friction

The core issue with editing Markdown on mobile is friction. Keyboards aren’t optimized for syntax symbols, and switching back and forth between edit mode and preview mode breaks your writing flow. Furthermore, standard AI writing assistants often strip away your markdown formatting or return poorly structured blocks that require manual cleanup.

I wanted an app that solved these specific issues:

1. Quick access to markdown syntax elements.
2. A live, side-by-side or tabbed preview that renders correctly.
3. An AI assistant that respects and works directly with Markdown structure.

The Tech Stack

To build a responsive editor, I selected a modern Android stack:

• Kotlin: For concise and safe code.
• Jetpack Compose: To build a declarative, fluid UI that adapts easily to different screen sizes and orientations.
• Markwon / Flexmark (adapted): For parsing and rendering Markdown to rich text in the preview.
• Coroutines: To handle parsing and AI generation off the main thread, keeping the UI responsive.

Technical Challenges

Two main challenges arose during development:

1. Real-Time Syntax Highlighting

In Jetpack Compose, the TextField component is powerful but can lag if you attempt heavy parsing on every keystroke. Applying syntax highlighting to the raw editor text in real-time meant writing a highly efficient, incremental parser. I had to throttle the highlighting updates to prevent the keyboard input from stuttering, especially on larger documents.

2. AI Integration that Understands Context

Integrating an AI writer meant teaching the assistant to output raw Markdown that fits seamlessly into the user's document. Instead of replacing the entire text, the AI needs to understand the cursor's location and generate contextually relevant headings, lists, or code blocks. This required carefully structured prompts and parsing the stream of incoming tokens to dynamically update the active editing block.

Lessons Learned

• Keep it local first: Relying entirely on cloud APIs can make a mobile app feel sluggish. Keeping as many editing operations local as possible—and streamlining network calls—is crucial for a smooth user experience.
• Keyboard accessory bars are essential: Adding a simple helper row above the virtual keyboard for quick symbols like hashes, asterisks, backticks, and brackets reduces the friction of writing Markdown by at least 80%.

Try It Out

If you've ever wanted to write or edit your technical documentation on the go without the usual hassle, you can try AIMarkdownPro Editor. It is available on Google Play. You can also learn more about the project at the AIMarkdownPro website, which is part of my solo developer portfolio at getinfotoyou.com.

I'd love to hear how you handle mobile writing workflows and what features you find most helpful.